// internal methods
internal MongoConnection AcquireConnection(ReadPreference readPreference)
{
MongoConnection requestConnection = null;
lock (_serverLock)
{
// if a thread has called RequestStart it wants all operations to take place on the same connection
int threadId = Thread.CurrentThread.ManagedThreadId;
Request request;
if (_requests.TryGetValue(threadId, out request))
{
if (!readPreference.MatchesInstance(request.Connection.ServerInstance))
{
throw new InvalidOperationException("The thread is in a RequestStart and the current server instance is not a match for the supplied read preference.");
}
requestConnection = request.Connection;
}
}
// check authentication outside of lock
if (requestConnection != null)
{
return(requestConnection);
}
var serverInstance = _serverProxy.ChooseServerInstance(readPreference);
return(serverInstance.AcquireConnection());
}
/// <summary>
/// Lets the server know that this thread is about to begin a series of related operations that must all occur
/// on the same connection. The return value of this method implements IDisposable and can be placed in a
/// using statement (in which case RequestDone will be called automatically when leaving the using statement).
/// </summary>
/// <param name="initialDatabase">One of the databases involved in the related operations.</param>
/// <param name="readPreference">The read preference.</param>
/// <returns>A helper object that implements IDisposable and calls <see cref="RequestDone"/> from the Dispose method.</returns>
public virtual IDisposable RequestStart(MongoDatabase initialDatabase, ReadPreference readPreference)
{
int threadId = Thread.CurrentThread.ManagedThreadId;
lock (_serverLock)
{
Request request;
if (_requests.TryGetValue(threadId, out request))
{
if (!readPreference.MatchesInstance(request.Connection.ServerInstance))
{
throw new InvalidOperationException("A nested call to RequestStart was made and the current instance does not match the nested read preference.");
}
request.NestingLevel++;
return(new RequestStartResult(this));
}
}
var serverInstance = _serverProxy.ChooseServerInstance(readPreference);
var connection = serverInstance.AcquireConnection();
lock (_serverLock)
{
var request = new Request(connection);
_requests.Add(threadId, request);
return(new RequestStartResult(this));
}
}
